Complications following biopsy of an intraabdominal or retroperitoneal mass compared with a renal mass.

Introduction: This study aimed to assess the short-term complication rate after US-guided core needle biopsies with an 18-gauge needle of retroperitoneal or intraabdominal masses (non-kidney group) compared with complications after biopsy from a renal mass (kidney group).

Methods: This was a retrospective analysis of 330 consecutive patients in the non-kidney group and 330 control patients in the kidney group. We recorded baseline characteristics, diagnostic yield, complications graded as Clavien-Dindo (CD) and readmissions within one and seven days.